Kianifard D., Zeinolabedini Daneshgar P., Dolatyari M The Study of Microscopic Structure of Testicular Seminiferous Tubules Following the Administration of Monosodium Glutamate in Paclitaxel Treated Adult Mice Kianifard D., Zeinolabedini Daneshgar P., Dolatyari M Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Objectives Results Chemotherapy is one of the risk factors which affect the fertility. Paclitaxel (PTX) is an effective chemotherapeutic agent and mitotic inhibitor which binds to DNA and prevents the DNA replication. PTX is used against a wide range of solid tumors. It has been reported numerous functional and structural alterations in testicular tissue following the administration of PTX. Monosodium glutamate (MSG) is the L-form of glutamic acid. Some studies indicated that monosodium glutamate can induce oxidative stress and has toxic effects on human and animal’s tissues. Male infertility and alteration of sperm production and morphology are the most reported changes in cases of MSG administration. In this study the effects of coadministration of PTX and MSG on the microscopic structure of seminiferous tubules (STs) was evaluated. The mean diameter of STs was reduced significantly in all groups in comparison to control group. Coadministration of PTX and MSG dose dependently led to more reduction in STs diameter. Tubular atrophy was observed in more degree following the administration of MSG after PTX. Conclusions Structural changes in testicular STs, following the administration of PTX can be related to fertility alterations. Oxidative compounds such as MSG can induce more structural and functional alterations of testicular tissue in cases of chemotherapies. Fig-2: Cross section of seminiferous tubules. A: control; B: PTX; C: PTX+MSG30; D: PTX+MSG60; E: MSG30+PTX; F: MSG60+PTX ST: Seminiferous Tubules AST: Atrophied Seminiferous Tubules Red Asterisks: Cellular population reduction Black Asterisks: Reduction in tubular diameter Black Arrows: Tubular structure alteration Red Arrows: Decline in germinal cells population Methods Paclitaxel (2 mg/kg i.p.) was administered to mice once per day for 5 consecutive days. MSG (30 & 60 mg/kg i.p.) was administrated for 28 days before or after PTX administration. Formaldehyde fixed testicular tissue samples were stained with hematoxylin and eosin method for quantitative evaluation of STs. References Borovskaya, T.G., Goldberg, V.E., Rumpel, O.A., Pahomova, A.V.,Perova, A.V., and Goldberg, E.D. (2009) The rat spermatogenesis after injection of paclitaxel (Antitumor Agent). Bull Exp Biol Med 147:715–718. Ahluwalia P, Tewari K, Choudhary P. Studies on the effects of monosodium glutamate on oxidative stress in erythrocytes of adult male mice. Toxicol Lett 1996; 84:161-5. Aitken RJ, Roman SD. 2008. Antioxidant systems and oxidative stress in the testes. Oxid Med Cell Longev; 1:15-24. Fig-1: Testicular tissue tubular diameter.